Film threading system



Aug. 24, 1943. J. BOLSEY 2,327,857

FILM 'IHREADING SYSTEM Filed Oct. 26, 1940 INVENTOR Patented Aug. 24, 1943 I UNITED STATES PATENT orricr;

FILM run-moms SYSTEM Jacques Bolsey, New York, N. Y. Application October 26, 1940, Serial Ne. 362,915

15 Claims.

My invention relates to motionpicture apparatus, and more particularly to means for automatic guiding and threading a film through such an apparatus.

It is the main object of my invention to provide for a motion picture apparatus a completely automatic threading system that shall require a minimum degree of mental and physical exertion for its manipulation on the part of the operator of said apparatus.

A further object of my invention consists in an automatic film-threading system for cinematographic apparatus provided with stationary guid- .ing and loop-forming members on both ends of the film gate of said apparatus.

Still a further object or my invention consists in a motion picture camera provided with my new film-threading system.

Another object of my invention consists in providing meanswhich are adapted to operate the loop-forming members of my new film-threading system automatically by opening and closing the cover of the camera casing.

In order to attain the aforesaid objects, I propose to provide in a motion picture apparatus a combination oi a film gate, stationary loop-formring members cooperating with this film gate, and means being adapted to shorten, after threading, the film loops formed by these stationary loopiorming members. It is self-evident that-especially for motion picture apparatus provided with.

means for intermittently advancing the film past the film gateloop-'forming members are necessary: in this case the film loops have to be shortened after threading to an extent as to allow free breathing of the film loops during the intermittent movement of the film past the film gate.

In accordance with a preferred embodiment of my invention I propose to provide only outer loop-forming members limiting the maximal size the film loop formed by these members; in th embodiment of my invention I do not prov... c. nncr loop-forming members, and thus I do not form by such inner and outer members a channel through which the film passesa I have further found that by giving these loop- ;ormlng members an arcuate form; and by guidmy; the film by other guiding means against the inner surfaces of these outer loopforming members the film forms, by its own resiliency, loops substantially along, these inner surfaces, After h aving formed these loops-I have to shorten them in order to get final operative loops being at a certain distance from the stationary loop-forming. members; thus, these shortened loops are not in contact with the stationary loop-forming merehers, and can freely breath during the intermittentmovernent of the film past the film gate.

I have further found it advantageous to arrange the means for shortening the loops substantially at one end of each of the loop-forming members and to have the other ends of these members cooperating with the film gate iri such a manner as to form, together with this gate, a

unit film way'. I

In order to attain substantially automatic guiding and threading of the film I provide, besides the loop-shortening means, separate means adapted to operate, after threading, these loopshortening means. In motion picture cameras these means for operating the loopshort'ening system are put into action automatically by closing of the camera cover, i. e., after the filmthreading has been finished and the camera is ready for taking pictures. g

The novel features which I- consider characteristic of my invention are set forth in particular in the appended claims. Theinvention itself, however; both as to its; construction and its method of operation, together with additional objects and' advantages thereof, will best be understood from the following description of specific embodiments. when read in connection with the accompanying drawing, in which: I

Fig. l is a view, in front elevation, showing the principal elements of the automatic threading system of a camera, immediately after threading,

Fig. 2 is a View, in front elevation, showing the sameautomatic threading system, after action of theloop-shorteningmeans,

Fig. 3 is across section of the camera, shown I in Fig. 1, along line 3-3,

Figs. 4 and 5 are plane views of different embodiments of the means for operating the loopshortening systemof the camera, and

Figs. 6, 7 and 8 are schematic plane views of various embodiments of my new loop-shortening system. I

1 shows a front elevation of my new camera. As usual, within camera casing I there are a supply,- 1. e., feed or unwinding reel 2, a take-up ree1'3, anda-film' gate 4. This film gate'comprises an aperture plate 5, a pressure plate 6, pins 1, guiding said aperture plate parallel to the pressure plate, and'a spring 8, by action of which the aperture plate is pressed against the picture gate 9.

The film I8 is unwoundfrem the supply reel 2 and is wound, after passage between picture gate 9 and aperture plate 5; on the take-up reel 3.

Means, not shown in the drawing, are provided for intermittently moving the film past the film gate, i. e., past the aperture plate 5. The actuation of the take-up reel and of the supply reel does not form part of my invention. In the same manner, the construction of the casing itself, the optical construction of the camera, the means for actuating the shutter do not form part of the present invention and are not illustrated in the drawing.

In all embodiments of my invention, shown in the drawing, I provide two stationary loopforming members I!) of arcuate shape; these members are fixed by screws II to the partition wall 12, arranged within the camera. casing. As stated above, these loop-forming members are to be shaped and mounted in such a manner that the film forms by its own resiliency loops i3 being in contact with the inner surface of these loop-forming members when the film is guided against the inner surface of these members, as shown in the drawing. This resiliency also causes that during threading the film moves along the inner surface of the first loop-forming member it], enters the space between aperture plate 5 and picture gate 9, and, after having passed this space, comes in contact with the second loop-forming member ID and is guided along the inner surface of this member back to the take-up reel 3. Thus, these stationary loopforming members are limiting the size of the loops i3 formed by these members themselves.

In my new camera shown in Figs. 1 to 5, transport sprockets I4 and guiding means, e. g., guiding plates i5 are arranged for guiding the film against and into contact with the loop-forming members IO, and for transporting it past the film gate.

In accordance with my invention, these transport sprockets l4 and the cooperating guiding I 22, pins 23, and cooperating slots 24 to the lever arms ll. By turning the guiding plates around the screws 22 as pivots, these guiding plates can be swung against and from the sprockets [4.

As shown in Fig. 3, the sprockets H are carried by stub shafts 25, passing through arcuate slits 26 provided in the partition plate l2. Stub shafts 25 carry at their other ends pinions 21, which are in mesh with the tooth crown 28; tooth crown 28 is secured to the casing 29 enclosing the camera spring and is carried by shaft 3'3. I want to note that shaft 30, carrying tooth crown 28, and shaft i9 carrying the lever-like members It are arranged coaxially, and thus the sprockets 24 and the pinions 21 move along circles being concentric with the tooth crown 28. Thus, when the lever arms I! are swung around their shaft IS the pinions 21 remain constantly in mesh with the tooth crown 28.

The method of operating my loop-shortening system is the following:

Cover plate 2i is secured to the end of When film loops are to be formed, the lever members [6 are swung in such a way that the lever arms l8 are near to each other, while the lever arms I! are distant from each other, as shown in Fig. 1. In this position the lever members l6 and sprockets l4 being inoperative, the film is formed into loops l3 along the inner surface of the loop-forming members It). The lever members l5 are then moved into operative position. In this movement, the sprockets ll will be positively turned through the engagement of the pinions 21 with crown 28, and will thus take up a part of the film loops I3. This loop-shortening" turning of the sprockets l4 is supported and supplemented by their additional swinging around their common shaft I9 in direction to each other, i. e., away from the loop-forming members ID. This combined movement of the film sprockets brings the film into the position shown in Fig. 2. In this position the film loops 3| are separated from the loop-forming members It, and far enough from them as to allow free breathing of the film loops during the intermittent movement of the film past the film gate.

I want to stress that the combination of these two movements, i. e., the turning and swinging of the sprockets I4 is not absolutely necessary: if the sprockets are turning in the above indicated direction without being swung, this tuming alone will have a loop-shortening effect; in the same way, their swinging in the direction as indicated by arrow 32, without any turning, would have a loop-shortening effect, too. However, the combined effect of turning and swinging enables to attain a relatively great shortening of the loops by a relatively small displacement, e. g., swinging of the sprockets.

In order to make operation of this loop-shortening system independent from the operator of the camera, I arrange, in a preferred embodiment of my invention, means being adapted to operate this system automatically, e. g. by opening and closing the camera cover. For this purpose an operating member 33, shown in Figs. 1, 3, and 4, is provided for. This member 33 is secured to the camera casing I slidably, in the direction of arrow 34. The slidable attachment is achieved by a longitudinal slot 35 in member 33 engaging with pins 36 fixed to the camera casing 1. One end of member 33 is provided with a projection 31 cooperating with the camera cover 33 in such a way that, when the camera cover is closed, member 33 is pressed against, 1. e., between lever arms IB of the lever members IS. The end of the member 33 engaging the lever arms i8 is provided with inclined faces. In pressing these inclined faces against the inner edges 39 of the lever arms l8, these lever arms are pressed from each other. It is self-evident that this movement of the lever arms 18 from each other results in a movement of the lever arms I! to each other.

For pressing the lever arms I! and the sprockets l4 carried by them from each other, a com pression spring 40 is provided; this spring is secured by pin H to the partition wall l2, and is pressing against the inner faces of arms IT.

The operation of this automatic operating system is the following: When the camera casing is open, i. e., during threading, the operating mem ber 33 is out of contact with the lever arms l8 and the compression spring 40 pushes lever arms I! from each other, i. e., the lever arms are in racemes? I 3 he. position shown in Fla. 1.v In this. position I am. able to vary the ng h o the film portio s loops are formed by members it. between said s r c et .5. a d the fr e end of the After threading, the camerav cover 3.3 isv closed. loop-.iorming members Hi. thereby varying, e. g., the operating member 33. Rushed between level shortening, after threading, the film loops in the arms l8, these lever arms pressed from. each 5 indicatedway to the desired extent. other, and the lever arms Ilare pressed thereby i want to stress that in the embodiments shown against the action of spring 4,0. to each other, in Rigs. 6 to 8 I" may use instead of guiding i. e., into the position shown in Fig. 2. In this rollers other guiding means, e. g., guiding plates position the loops are shortened and the camera being similar to the guiding plates 15 shown in ready for operation. Fig. 1.

Fig. 5 shows a modified embodiment of an It will also be understood that each of the eleoperatlng member adapted for a system which is merits above described, or-two or'more together, not equipped with compression spring 40'. In myalsofindauseful application in other types this case. the operating member. 42 has the shape of cinematographic apparatus differing from the shown in Fig. 5. Spring L 3; cooperating with types described above. pin 45. being secured to. the camera casing, While- I have illust at d. nd ib d he inpresses this member 42 constantly upwards v n ionas embodied in cinematograp ppaagainst the camera cover 38.; thus, when closed, ratus, I do not intend to be limited to the cl ethe cover as engages edge M, of. me b r. 42', pi tails shown, sincevarious modifications and struc- 4d and slots 4.! are provided in order toenable g0 tulial h n e ay b made witho d p i g in sliding of operating member. 42 in the. direction a y wav i om thc'spi it o y inVentiOnindicated by arrow 41' along the camera wall. W at I a m a new d re to Secure by For engaging the ends, of thelever arms [8 a L e a e 151 cut-out 48, having the shape as shown in Fig. 5, 1. In- 8 mo ion picture app film gate, is provided for in member 42. This cut-out is a na lo -r members p rat n provided with two inclined inner faces 49 and w v id fi m a r substantiafly automatic two inclined outer faces 50; the inner faces enthreading Of fi W transport Sprockets gage the inner edges 39, and the outer faces 50 spo ti Said fi through Said pp engage. the outer edges 51 of the lever arms 18. WW) film guides, each arranged between One Of It is self-evident, and needs no further detailed 30 said Sprockets and Said m loop-forming explanation and description, that by movement of members d g the, film transported y Said the operating member in the direction indicated Sprockets against the inner faces of said byarrow 41 the leverarms [8 are guided to and tionaly Q p' b z i compelling therefrom each other, moving thereby lever arms I! by 53 m, t0 mO-VE f g S d inner faces of Said and sprockets it, carried bythem in the needed Stationary loopdormine members and past said manner. As the movement of this operating film e, a members h Carrying one member 42 is achieved by closing and opening 05 d Sprockets-and one of said film guides slid of the camera. cover only, operation of the loopablrbetween o p ons o e of which is nearer shortening system by this operating member is o he corresponding Icon-forming member a automatic, and does not need separate actions =10 otherlferthertherefrom, enabling thus m by t operatoriof t m. ing of said sprockets and said film guides after Fjg. 6 Shows a 1 p fonnjn and Shortening threading from said nearer to said farther posisystem in which two stationary transport sprocki fi ffl Sh g the m 1 P s ets 52 are provided for/ These sprookets are n a fifi e t di i t members and driven in the usual way. The stationaryarquate l moving h e 1 p portions out of contact loop-forming members [0 are arranged substane l? m e m tially the same manner as describedabove in n t m n picture apparatus, an w l connection with the embodiment of my invention m gate p is n an pe e p te shown in Figs. 1 to 4. In order to vary the size and r Plate; means for intermittently f the 6 formed by'these loop 'shcrtemng 5o advancing a film past said film gate, two stationbers lflptwo guiding means, e. g., guiding rollers ary arcuate outer loop-forming members, one end 53 are provided for; these guiding rollers are ad. of each of: said loop-forming members cooperating justably movable in such a manner as to Vary with, said aperture plate, said stationary loopby their movement the length of'the film between forming members thus serving for continuous outer guiding and: automatic threading of said the sprockets 52 and the loop-forming members '03 in order to shorten by their movement the film through said. apparatus. two transport length ofthe loop formed by these members, sprockets, transporting said film, film guides Th for instance, th rollers may be m ov arranged between said sprockets and said loopable in the direction indicated by arrow 54 in forming members. guiding the film transported t i case t mners are swung. Mt threading by said sprockets against the inner faces of said f, the film into position 5 a thereby the stationary arcuate outer loopeforming members, loops are shortened, as indicated in: dotted lines. compelling thereby SPF-id film a 316m; Said The embodiment, f mm shown in inner faces of: said loop-forming members and Fig. '7 is substantiallyidenticalwiththe embodipast said film g d pp t m mbers ment shown 111mg 1 differenc being movably secured tosaid apparatus body and that for transporting the film, one stationary carrying s d Sprockets and film d s slidab e sprocket 53 is arranged only, instead oi two, between two positions one of which is nearer to In Fig. 8a furthermodined embodiment of my e r ponding loop-forming member and the invention is shown. In this embodiment proother fart-her therefllfl'm, n b g thus moving vide for two. stationary. guiding rollers-54"; I aid p ockets and. said film. id s f e further arrange a transport sprocket 55; being threading from said nearer tosaid farther posiadjust-ably movable in directionof arrow 56', i. e., tion, thereby shortening the film loop portions substantially normalato ,theplaneofsthefllm gate; being adjacent to said loop-forming members and i ,5, by. IlQYinfisprockeh-ii in theindicated dimoving these film. loop. portions out of contact rection int0.thcposltionindicatedzby dotted lines, with theseloopeforming members.

3. In a motion picture apparatus according to arranged between said lever arms, means operclaim 2, in combination lever-like members, each ated by said camera cover being adapted to alof them carrying near its outer end one of said low action of said spring member when said movable sprockets and a gear driving said camera cover is opened, and to avoid action of sprockets, said lever-like members being adaptsaid spring when said cover is closed, thus ened to swing about a common shaft, and a main abling sho te 0f t fi 100138 formed y driving gear mounted coaxially with said swing- S d op-f m members y Closing the c v r able lever-like members and being in mesh with the Cameraboth gears carried by these members, 8. In a motion picture camera, a camera cas- 4. In a motion picture apparatus accordin to i ing provided with a camera cover, a film gate, a claim 2, means being adapted to hold said Stationary p-f me p rat n sprockets during threading of the film at a cer- With Said film gate for Substantially automatic tain distance from each other, and means being threading Of a fi m ug Sa d camera and adapted to diminish the distance between said moving the Same P st d fi m ate, fi m transsprockets after threading, thus shortening the porting mea s Cooperating With Said Stationary film loops formed by said stationary loop-formloop-forming e sa d fi m sp t ing members, one of said means being a spring means being secured to said apparatus body member acting automatically when released, and Slidabie between tWO positions On of which is the other being mechanical means being adapted nearer t0 Said Stationery p-f r n member t b perated by th user of i apparatus and the other farther therefrom, enabling thus 5. In a motion picture apparatus according to moving Said fi m t po ea s after claim t 1 1;: members, each of t threading from said nearer to said farther posiconsisting of two lever arms turning about a tion, thereby Shortening the p po tio common shaft, and each of them carrying near being adjacent to S d s ationary loop-forming the end of one of these lever arms one of said member and moving this p-p o out of sprockets in Such a manner as to be adapted to contact with this member, and means operated change, by turning of said lever-like members by said camera cover automatically sliding said about said shaft, the length of the film loops Sprocket from said noarerto d t e pos tion formed by said stationary loop-forming me when said camera cover is closed and automatibers. 3U a y sliding said sprocket from said farther to I a motion picture apparatus a fil gate, said nearer position when said camera cover is comprising an aperture plate and a pressure Openedplate, means for intermittently advancing the In a motion p cture camera a camera casfilm past said film gate, two stationary arcuate mg Provided With a a e a Cover, a film gate outer loop-forming members, one end of each of Comprising an apeftureplate a d a pressure said loop-forming members cooperating with P means for intermittently edveneing e said aperture plate, thus serving for continuous film P Said film gate, W Stat onary arcuate outer guiding and automatic threading of the Outer loop-forming members, O e e d of each of film through said apparatus, two movable transsaid loop-forming members p a ng with port sprockets, film guides cooperating with said Said aperture P Serving e eby for continu- Sprockets Said sprockets and Said film guides ous outer guiding and automatic threading of the being adapted to move the film along the inner fi through s d p t s, tw sp t surface of said loop-forming members and past Sprockets, film guides pe ti g with said said film gate, two lever-like members, each of Sprockets, said sprccketfi and Enid film u des them consisting of two lever-arms turning about being adapted to move the fi a ong the inner a common shaft and each of them carrying near Surface of Said loop-forming members nd past its end one of said sprockets in such a manner S film gate and being ar a t t e other as to be adapted to shorten the peripheric length ends of Said loop-firming embers movable subof the film loops by diminishing the distance Stantiaily parallel to the plane of the m at between the lever arms carrying the sprockets, means adapted to autcmatieaily Slide Said transand means being adapted to hold said lever arms porting sprockets in direction to each other when during threading apart from a h th said camera cover is closed, and means adapted 7 In a motion picture camel-a a camera to automatically slide said transport sprockets m equipped with camera Cover, a fi1m-f din away from each other when the camera cover is mechanism within said camera casing, said Openedfiinl-feeding mechanism comprising a film gate 9- In a motion Picture apparatus, a fi m 81(- with an aperture plate, means for intermittently Poslng member, & m transportin ember, Staadvancing the fil past said m gate two tionary film threading means extending between tjonary arcuate Outer loop formjng members, said members and forming an outer substantially one end of each of said loop-forming members arcuate film guide y which t e fi is u ed cooperating with said aperture plate, thus servautomatically om One Of Said members to the m for continuous Outer guidinrr and automatic other when it is moved past one of said members threading of the film through said apparatus, against Said film threading s, and a movtwo movable sprockets, film guides cooperating e upp Carrying Said fi a po ti g with said sprockets, said sprockets and said film member slidably between O po t ons one of guides being adapted to move the film along the which is nearer to said film threading means and inner urfa e of said lgop formjng members nd the other farther therefrom, moving thereby the past said film gatetwo lever-like members, each film formed by Said fi threading eans of them consisting of two lever-arms turning about t Of Contact with the same.

a common shaft and each of them carrying near In 81 motion picture pp r tus, a film exits one end one of said sprockets in such a manposing member, a. film transporting sprocket her as to be adapted to shorten the length of the member, Stationary film threading means exfilm loops formed during threading by diminishing the distance between the lever arms carrying the sprockets, a compression spring member tending between said members and having an inner substantially arcuate film guiding face by which the film is guided automatically from one of said members to the other when it is moved past one of said members against said inner v arcuate film guiding face, and a movable support carrying said film transporting sprocket member slidably between two positions one of which is nearer to said film threading mean and the other farther therefrom, thereby moving the film loop formed by said film threading means out of contact with the same. 1

12. In a motion picture apparatus, a film exposing member, a film guiding idler roller member, stationary film threading means extending between said members and having an innner substantially arcuate film guiding face by which the film is guided automatically from one of said members to the other when it is moved past one of said members against said inner arcuate film guiding face, and a movable support carrying said film guiding idler roller member slidably between two positions one of which is nearer to said film threading means and the other farther therefrom, thereby moving the film loop formed by said film threading means out of contact with the same.

13. In a motion picture apparatus, a film gate, two film transporting members, two stationary lni threading means, one of said film threading means extending between one of said film transporting members and said film gate and forming an outer substantially arcuate film guide by which the film is guided automatically from said film transporting member to said film gate when it is moved by said film transporting member against said film threading means, the other of said film threading means extending between said film gate and the other of said film transporting members and forming an outer substantially arcuate film guide by which the film is guided automatically from said film gate to said other film transporting member when it is moved past said film gate against said film threading means, and at least one movable support carrying said film transporting members slidably between two positions in one of which each of said film transporting members is nearer to the corresponding stationary film threading means and in the other of which each of said film transporting means is farther from said corresponding film threading means moving thereby the film loops formed by said stationary film threading means out of contact with the same.

14. In a motion picture apparatus, a film gate, two stationary film guiding means arranged at a certain distance from said film gate so as to allow formation of a film loop between said guiding means and said film gate, two stationary film threading means, one of said film threading means extending between one of said film guiding means and said film gate and forming an outer substantially arcuate film guide by which the film is guided automatically from said stationary film guiding means to said film gate when it is moved past said film guiding means against said film threading means, the other of said film threading means extending between saidfilm gate and the other of said film guiding means and forming an outer substantially arcuate film guide by which the film is guided automatically from said film gate to said other film guiding means when it is moved past said film gate against said other film threading means, and a transport sprocket co-operating with said guiding means and engaging the film before it has passed one of said guiding means and after it has passed the other of said guiding means, said sprocket being adjustably movable in such a manner as to vary the length of the film portions between said sprocket and said film guiding means.

15, In a motion picture apparatus, a film gate, two stationary film guiding idler rollers arranged at a certain distance from said film gate so as to allow formation of one film loop between said film gate and each of said idler rollers, two stationary film threading means, one of said film threading means extending between one of said idler rollers and said film gate and having an inner substantially arcuate film guiding face by which the film is guided automatically from said idler roller to said film gate when it is moved past said idler roller against said inner arcuate film guiding face, the other of said film threading means extending between said film gate and the other idler roller and having also an inner substantially arcuate film guiding face by which the film is guided automatically from said film gate to said other idler roller when it is moved past said film gate against said inner arcuate film guiding face of said other film threading means, and a transport sprocket cooperating with said idler rollers and engaging the film before it has passed one of said idler rollers and after it has passed the other of said idler rollers, said transport sprocket being adjustably movable substantially normal to the plane of said film gate, thereby varying the length of the film portions between said sprocket and said idler rollers and moving the film loops formed by said stationary film threading means out of contact with the same.

JACQUES BOLSEY. 

